The Research On Fatigue And Durability For Injection Valve Of The Gas Fuel Engine

Electric injection valve is an important part of the engine fuel injection system with its high working frequency and big interaction force which influence the precision of gas injection and the fatigue life reliability.The dynamic response characteristic and the fatigue life prediction can be solved quickly and efficiently by the method of establishing the model using the Matlab/Simulink and Ncode which is an important method of the fatigue life reliability problem.In this paper,the injection valve had been studied with combining experiment and numerical simulation on its dynamic response characteristic and the fatigue life in different structure parameter such as voltage,number of coil turns,preloaded spring force,clearance between the electromagnetic part and stem besides a dynamics model has been established for the injection valve by the method of using Matlab/Simulink.At last an orthogonal table arranged in nine groups is established to analyze the fatigue life in different loading case and the optimization parameters is got by the method of range analysis and variance analysis.The experiment and numerical simulation have been done to enhance the fatigue life reliability using the optimization structure parameters.The research results showed several aspects.Higher the driving voltage is,shorter the valve opening time is,but the overtop driving voltage dose little influence on valve opening time.The low maintenance voltage plays an impact on the delay time of stem,but dose no influence on the moving time of the stem.The preloaded spring force dose little influence on the opening time,but has an impact on the closing time that smaller the preloaded spring force is,less the closing time is.More coil turns is,higher the peak of electromagnetic force is and longer the opening time is and shorter the closing time is.Smaller the clearance between the stem and the electromagnet part is,shorter the opening and closing time is.Variance analysis table indicates that the effect of voltage,number of coil turns,preloaded spring force,clearance between the electromagnetic part and stem on the fatigue life is non-significant,but decreasing the preloaded spring force can increase the fatigue life of the valve.The experiment and numerical simulation with optimal parameters indicates that the results of the numerical simulation can be accepted which increases the life of the valve from8.6?10⁷ to 1.01?10⁸ and enhance the fatigue life reliability.